Computer Implemented Method for Authenticating a User

1. A computer implemented method for performing a user authentication, the method comprising the following steps performed on a hardware processor: generating a private and a public key, comprising the following steps: entering a user-selected secret, storing the user-selected secret in memory, computing the private key by applying an embedding and randomizing function onto the secret and additional values, storing the private key in memory, computing the public key using the private key, the public key and private key forming the asymmetric cryptographic pair, and erasing the secret and the private key from memory, associating an asymmetric cryptographic key pair with the user, said user having an identity, said key pair comprising the public key and the private key, selecting the user to be authenticated using a pseudonym of said user, wherein said pseudonym comprises the public key of the user, wherein information linking said pseudonym to said identity of said user is not stored, and performing cryptographic authentication of the user using the asymmetric cryptographic key pair.

2. The method of claim 1 , wherein the cryptographic authentication comprises a challenge-response procedure for the user authentication, said procedure comprising: selecting and sending challenge data to the user, receiving in response to said sending encrypted challenge data, and decrypting the encrypted challenge data using the public key of the user, said decryption resulting in decrypted challenge data, or selecting challenge data and encrypting said challenge data with the public key of the user, said encrypting resulting in encrypted challenge data, sending the encrypted challenge data and receiving in response to said sending decrypted challenge data, wherein the user is authenticated in case the decrypted challenge data matches the challenge data.

3. The method of claim 1 , wherein the pseudonym corresponds to the public key of the user.

4. The method of claim 1 , further comprising determining when a public key certificate for the public key exists, wherein the successful user authentication requires the existence of the public key certificate.

5. The method of claim 4 , further comprising validating the public key certificate, wherein the successful user authentication requires a successful validation of the public key certificate.

6. The method of claim 5 , wherein the determination when the public key certificate for the public key exists comprises sending a query to a certificate authority or a trusted entity, wherein the query comprises the public key, wherein in response to said query the public key certificate is received.

7. The method of claim 1 , wherein the method is performed in an online community.

8. The method of claim 1 , wherein the cryptographic authentication comprises a challenge-response procedure for the user authentication, said procedure comprising: receiving challenge data by the user and returning in response to said reception encrypted challenge data, wherein the challenge data is encrypted with the private key of the user, Or receiving encrypted challenge data by the user, decrypting said encrypted challenge data using the private key of the user and returning the decrypted challenge data.

9. The method of claim 1 , wherein the embedding and randomizing function comprises: applying a first one-way function on the secret to provide a first value, providing a random number, embedding the random number and the first value by combining them to provide a combination, and applying a second one-way function on the combination to provide a second value, wherein the second value constitutes the private key.

10. The method of claim 9 , wherein the computation of the public key is performed by ECC cryptography.

11. A non-transitory computer readable medium encoded with program capable of execution on a computer, the program comprising the following steps: generating a private and a public key, wherein generating the private key and public key comprising the following step: entering a user-selected secret, storing the user-selected secret in memory, computing the private key by applying an embedding and randomizing function onto the secret and additional values, storing the private key in memory, computing the public key using the private key, the public key and private key forming the asymmetric cryptographic pair, and erasing the secret and the private key from memory, associating an asymmetric cryptographic key pair with the user, said user having an identity, said key pair comprising the public key and the private key, selecting the user to be authenticated using a pseudonym of said user, wherein said, wherein information linking said pseudonym to said identity of said user is not stored, and performing cryptographic authentication of the user using the asymmetric cryptographic key pair.

12. A computer system for user authentication, the system comprising: a hardware processor, an asymmetric cryptographic key pair associated with the user, said user having an identity, said key pair comprising a public key and a private key, and pseudonym associated with the user to be authenticated, wherein said pseudonym comprises the public key of the user, wherein information linking said pseudonym to said identity of said user is not stored, the system being adapted for performing on a hardware processor a cryptographic authentication of the user using the asymmetric cryptographic key pair, wherein the hardware processor adapted to generate the private and the public key, by receiving a user-selected secret, storing the user-selected secret in memory, computing the private key by applying an embedding and randomizing function onto the secret and additional values, storing the private key in memory, computing the public key using the private key, the public key and private key forming the asymmetric cryptographic pair, and erasing the secret and the private key from memory.